Power module and air conditioner

ABSTRACT

An efficient heat diffusing structure comprising a power module having a mounting substrate that has a high thermal conduction efficiency. The mounting substrate is comprised of a mounting surface on which an electric power circuit for controlling electric power is mounted, and a heat dissipating surface that has a corrugated section formed thereon that serves to dissipate heat. This heat diffusing structure allows the size of the device to be reduced, and also allows costs to be reduced.

TECHNICAL FIELD

The present invention relates to a power module and an air conditionercomprising a power module. More particularly, the present inventionrelates to a heat dissipating structure for improving the heatdissipating efficiency of a power module on which circuit componentsthat generate a great deal of heat are mounted, and the modulization ofa power module that uses an inverter circuit to convert commercial acpower to ac power having a predetermined frequency.

BACKGROUND ART

In order to control a device at a predetermined frequency, an invertercircuit will be used to rectify commercial ac power to dc power, andthen convert the dc power to ac power that is controlled at apredetermined frequency.

The inverter circuit is formed by combining a rectifying stack, asmoothing condenser, a power transistor, and the like. These circuitcomponents continue to be integrated, and an intelligent module whichpackages a drive circuit and a power element together is now beingmarketed. In addition, one type of electric power unit needed to drivethe inverter includes a converter that rectifies commercial ac power todc power, and improves harmonic suppression and efficiency. Moreover, ithas been proposed that this electric power unit employs a power switchand the like.

The converter that converts commercial ac power to dc power, and theinverter that converts dc power to ac power of a predeterminedfrequency, are comprised of heat generating components such as diodesand power switches, and thus must include a heat dissipating structure.For example, it is possible to achieve a cooling effect on theelectrical components by using an aluminum substrate to mount theelectrical components, due to the cooling effect provided by the surfaceof the aluminum substrate that is opposite the mounting surface.

However, because the integration of these electrical componentscontinue, a great deal of heat will be generated thereby and the heatdissipating capabilities of the aluminum substrate will be insufficient.Because of this, it is thought that the heat dissipating capabilitieswill improve by fixing a large number of plate shaped heat dissipatingfins onto the bottom surface of the aluminum substrate.

When the heat dissipating plates are added, efficient heat transfercannot be expected at the connecting surface between the aluminumsubstrate and the heat dissipating fins because the portion thatconnects these two elements has a great deal of heat resistance. Inorder to address this problem, increasing the size of the heatdissipating fins to increase the heat dissipating capacity thereof hasbeen considered. However, this will increase the overall size of thedevice and make it difficult to lower costs.

It is an object of the present invention to provide a power module thathas an efficient heat dissipation structure, that is small, and thatallows cost to be lowered.

In addition, because there are many instances in which the converter andinverter are placed in barracks or in specialized modules, the shape ofthe completed component is large, the thermal design thereof must takeinto consideration its spatial layout design and thermal state, and thedesign of the converter and inverter will be extremely difficult.

In addition, a controller for controlling the inverter circuit iscomprised of a microcomputer, and the controller and the invertercircuit are connected by a harness or the like. When a drive signal istransmitted via this harness, there is a concern that noise will beeasily transferred and be involved in malfunctions.

Furthermore, there are other problems that it is difficult to diagnose afailure part, it is difficult to specify the components to exchange andit is complicate to exchange a component, since the control of theinverter is high efficient.

Because there is a great deal of exposed solder, component lead, and thelike for mounting each component, there is also a concern that trackingaccidents will occur due to the infiltration of corrosion, dust, orsmall animals therein.

Operational control of an air conditioner is conducted by controllingthe amount of refrigerant that circulates in the refrigerant circuitwith the compressor. This type of compressor uses an inverter circuit tocontrol the operational frequency thereof, and thus includes theproblems with the inverter circuit described above. In particular, it isdesirable for the air conditioner to be made compact by reducing thesize of each component therein, and to simplify the layout and thermaldesign thereof. Furthermore, there is a need to prevent malfunctions dueto the effects of noise, as well as a need to prevent the ill effects ofcorrosion, dust, and the infiltration of small animals therein. Inparticular, when the inverter circuit is installed in the outdoor unitof an air conditioner, there are concerns about the deteriorationthereof that accompanies environmental changes such as temperaturevariations over a long period of time and wind and rain, and theinfiltration of insects and other small animals. The effects of theseproblems need to be eliminated to the greatest degree possible.

It is another object of the present invention to provide a power modulethat is constructed such that the portions thereof that are exposed,such as the harness, the solder, and component leads, are reduced to thegreatest degree possible, the effects of noise are eliminated, theeffects of corrosion, dust, and the infiltration of small animals areeliminated, and special layout and thermal designs are not necessary.

DISCLOSURE OF THE INVENTION

A power module according to claim 1 of the present invention iscomprised of a bare chip component that forms an electrical powercircuit for controlling electrical power, a mounting substrate on whichthe bare chip component is mounted, and a molding material formed froman insulating resin that molds to the surface of the mounting substrateon which the bare chip component is mounted.

In the power module according to claim 1 of the present invention, theconnection between the bare chip component and the wiring on themounting substrate can be formed by wire bonding and the like. Becausethis wiring is covered by means of the molding material, the wiring canbe shortened and the effects of noise can be eliminated. In addition,because exposed portions will be eliminated, ill effects from theinfiltration of corrosion, dust, and small animals can be prevented.

The power module according to claim 2 of the present invention is thepower module disclosed in claim 1, in which a plurality of bare chipcomponents are mounted on the mounting substrate.

In the power module according to claim 2 of the present invention, theconnection between the bare chip components and the wiring on themounting substrate can be formed by wire bonding and the like. Becausethis wiring is covered by means of the molding material, the wiring canbe shortened. When a large number of components generate heat, the powermodule can be constructed such that the heat is dissipated via thealuminum substrate.

The power module according to claim 3 of the present invention is thepower module disclosed in claims 1 or 2, in which the bare chipcomponent includes an IC chip that is mounted on a printed wiring boardthat is mounted on the mounting surface.

In the power module according to claim 3 of the present invention,circuit components that produce a great deal of heat can be insulatedfrom those that produce comparatively little heat by forming the printedwiring board on which the comparatively low heat generating circuitcomponents are mounted into a hybrid shape.

The power module according to claim 4 of the present invention is thepower module disclosed in claims 1 to 3, in which the mounting substratehas heat dissipating fins that are integrally disposed on the surfaceopposite the surface on which the bare chip component is mounted.

In the power module according to claim 4 of the present invention, ifcomparatively high heat generating circuit components are mounted on topof the mounting substrate as bare chip components, heat can beefficiently dissipated therefrom via the heat dissipating fins, andcircuit malfunctions can be prevented by maintaining them at a suitabletemperature.

The power module according to claim 5 of the present invention is thepower module disclosed in claims 1 to 4, and further comprises sidewalls that are disposed on the edges of the mounting substrate and whichextend above the surface on which the bare chip is mounted, and in whicha molding material is disposed inside the space formed by the mountingsubstrate and the side walls.

In this configuration, the task of filling the space formed by themounting substrate and the side walls with the molding material can bemade easy, and the bare chip component mounting surface of the mountingsubstrate can be accurately covered.

The power module according to claim 6 of the present invention is thepower module disclosed in claim 5, in which the side walls are comprisedof plate shaped members that are formed from a synthetic resin and inwhich a conductive pattern is embedded.

Here, it becomes possible to use the conductive pattern embedded in theinterior of the side walls to connect the circuit elements, and it alsobecomes possible to mount circuit elements such as electrolyticcondensers and the like that are difficult to integrate.

The power module according to claim 7 of the present invention is thepower module disclosed in any of claims 1 to 6, in which the bare chipcomponent includes an inverter circuit that converts commercial ac powerto ac power having a predetermined frequency, and a controller thatcontrols the frequency output from the inverter circuit.

Here, by directly mounting the inverter circuit and the controller forthe inverter circuit to the mounting substrate as bare chip componentsand modulizing them, it will not be necessary to again consider thespatial layout and thermal design of each component, the effects ofnoise will be eliminated to the greatest degree possible by shorteningthe wiring distances, and the infiltration of corrosion, dust and smallanimals will be prevented.

The power module according to claim 8 of the present invention is thepower module disclosed in claim 7, in which the inverter circuit iscomprised of a converter that rectifies commercial ac power to dc power,an inverter that converts the output of the converter to ac power, aconverter driver that drives the converter, and an inverter driver thatdrives the inverter.

Here, each power module can be comprised of one or a plurality of barechip components, and the bare chip components can be mounted on thealuminum substrate. Thus, it will not be necessary to again considerspecialized spatial layout and thermal designs thereof.

The power module according to claim 9 of the present invention is thepower module disclosed in claim 7 or 8, in which the inverter circuitcontrols the electric power supplied to a compressor in an airconditioner, the compressor controlling the amount of refrigerantcirculating in a refrigerant circuit.

Here, by modulizing the inverter circuit that controls the compressor ofthe air conditioner, the size of the device can be reduced, the effectsof noise and ill effects from the infiltration of corrosion, dust andsmall animals can be eliminated, and a highly reliable device can beprovided. In addition, by viewing the power module as one component andconducing structural design accordingly, it will not be necessary tohave a different structural design for each type of compressor mountedin the air conditioner, and thus the number of man-hours needed forstructural design with respect to the large number of different types ofcompressors available can be greatly reduced.

The power module according to claim 10 of the present invention is thepower module disclosed in claim 9, in which the air conditioner iscomprised of a fan that produces an air flow that exchanges heat withrefrigerant inside a heat exchanger disposed inside the refrigerantcircuit, and a fan motor that rotatively drives the fan. In addition,the bare chip component further includes a fan motor controller thatcontrols the rotation of the fan motor.

Here, the size of the device can be reduced by mounting the fan motorcontroller comprising bare chip components onto the aluminum substratetogether with other circuit components and modulizing them, thuseliminating the need to again consider the spatial layout and thermaldesign thereof.

An air conditioner according to claim 11 of the present invention iscomprised of an air conditioning unit that exchanges heat between airdrawn therein and refrigerant that circulates inside a refrigerantcircuit and then supplies the heat exchanged air to an indoor space, andan electric power unit that controls the electric power supplied to theair conditioning unit. The electric power unit is comprised of amodulized power module that is comprised of a bare chip component thatforms an electric power circuit for controlling electric power, analuminum substrate on which the bare chip component is mounted, and amolding material that is formed from an insulating resin and which moldsthe surface of the mounting substrate to which the bare chip componentis mounted.

Here, by modulizing the electric power unit of the air conditioner, thesize of the device can be reduced, the effects of noise and theinfiltration of corrosion, dust and small animals can be eliminated, anda highly reliable device can be provided.

The air conditioner according to claim 12 of the present invention isthe air conditioner according to claim 11, which further comprises acompressor that controls the amount of refrigerant circulating in therefrigerant circuit, and the bare chip component controls the electricpower that is supplied to the compressor and includes an invertercircuit that converts commercial ac power to ac power of a predeterminedfrequency, and a controller that controls the frequency of the output ofthe inverter circuit.

Here, the effects of noise can be eliminated by modulizing the electricpower unit that serves to control the electric power supplied to thecompressor of the air conditioner. In addition, although there is aconcern that insects, dust, and the like will infiltrate an indoor unitof a separate type of air conditioner because the outdoor unit thereofis placed outside, foreign objects such as small animals and dust thatenter into the electric power unit can be prevented from causingproblems such as short circuiting and the like.

The air conditioner according to claim 13 of the present invention isthe air conditioner according to claim 11 or 12, in which the airconditioner further comprises a fan that produces an air flow thatexchanges heat with refrigerant inside a heat exchanger disposed insidethe refrigerant circuit, and a fan motor that rotatively drives the fan.In addition, the bare chip component further includes a fan motorcontroller that controls the rotation of the fan motor.

Here, the size of the device can be reduced by including and thenmodulizing the fan motor controller that controls the rotation of thefan motor of the air conditioner, and thus a highly reliable device inwhich the effects of noise and the infiltration of corrosion, dust, andsmall animals are eliminated.

A power module according to claim 14 of the present invention has amounting substrate that is formed from a member having a high thermalconduction efficiency that comprises a mounting surface on which anelectric power circuit for controlling electric power is mounted, and aheat dissipating surface on which a corrugated section for heatdissipation is formed.

Here, the heat generated by the circuit components mounted on themounting surface can be efficiently dissipated by means of thecorrugated section formed on the heat dissipating surface of themounting substrate.

The power module according to claim 15 of the present invention is thepower module disclosed in claim 14, in which the mounting surface andthe heat dissipating surface form a two-sided mounting substrate.

Here, heat can be efficiently dissipated from the heat dissipationsurface even if the mounting surface is molded with an insulatingsynthetic resin and an enclosed type of module is formed.

The power module according to claim 16 of the present invention is thepower module disclosed in claim 14 or 15, in which the mountingsubstrate comprises a plate shaped substrate formed from an aluminumtype of metal and which has a copper wiring pattern formed on one sidethereof.

Here, the heat from the circuit components mounted on the mountingsurface can be efficiently dissipated because an aluminum type of metalhaving a high thermo-electric conductivity is used as the mountingsubstrate.

The power module according to claim 17 of the present invention is thepower module disclosed in any of claims 14 to 16, in which heatdissipating fins comprising an attachment surface that attaches to theheat dissipating surface of the corrugated section, and a fin formationsection on which plate shaped fins are disposed, are installed on theheat dissipating surface of the mounting substrate.

Here, the attachment surface of the heat dissipating fins has acorrugated shape such that it attaches to the heat dissipating surfaceof the mounting substrate, and the thermal conductive efficiency betweenthe heat dissipating fins and the mounting substrate is improved. Thus,the heat generated from the circuit components mounted on the mountingsubstrate can be efficiently transmitted to the heat dissipating fins,and the efficiency of thermal dissipation can be improved.

The power module according to claim 18 of the present invention is thepower module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions havingrectangular cross-sections and which are formed parallel to each other,and grooves that are formed between adjacent protrusions.

Here, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are rectangular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency thereof isimproved.

The power module according to claim 19 of the present invention is thepower module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions that aretriangular in cross-section and which are formed parallel to each other,and grooves that are formed between adjacent protrusions.

Here, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are triangular incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency thereof isimproved.

The power module according to claim 20 of the present invention is thepower module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions that aretrapezoidal in cross-section and which are formed parallel to eachother, and grooves that are formed between adjacent protrusions.

Here, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions that are trapezoidal incross-section and the grooves formed in between the adjacentprotrusions. In addition, when the heat dissipating fins are installed,the thermal dissipation effect can be improved because the contactsurface area between the heat dissipating surface of the mountingsubstrate and the attachment surface of the heat dissipating fins isenlarged, and the mutual thermal transmission efficiency thereof isimproved.

The power module according to claim 21 of the present invention is thepower module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of plate shaped protrusions that aresemi-circular in cross-section and which are formed parallel to eachother, and grooves that are formed between adjacent protrusions.

In the power module according to claim 21 of the present invention, thesurface area of the heat dissipating fins of the mounting substrate canbe enlarged, and the heat dissipation efficiency can be improved, bymeans of the protrusions that are semi-circular in cross-section and thegrooves formed in between the adjacent protrusions. In addition, whenthe heat dissipating fins are installed, the thermal dissipation effectcan be improved because the contact surface area between the heatdissipating surface of the mounting substrate and the attachment surfaceof the heat dissipating fins is enlarged, and the mutual thermaltransmission efficiency thereof is improved.

The power module according to claim 22 of the present invention is thepower module disclosed in any of claims 14 to 17, in which thecorrugated section is comprised of a plurality of protrusions havingtips thereof that are hemi-spherical in shape.

Here, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the plurality of protrusions whose tips arehemispherical. In addition, when the heat dissipating fins areinstalled, the thermal dissipation effect can be improved because thecontact surface area between the heat dissipating surface of themounting substrate and the attachment surface of the heat dissipatingfins is enlarged, and the mutual thermal transmission efficiency thereofis improved.

The power module according to claim 23 of the present invention is thepower module disclosed in claim 17, in which the heat dissipatingsurface of the mounting substrate and the attachment surface of the heatdissipating fins comprise protrusions whose tips have a shape incross-section which bulges outward toward the sides thereof further thanthe base thereof, and grooves which are received in between adjacentprotrusions.

Here, the surface area of the heat dissipating fins of the mountingsubstrate can be enlarged, and the heat dissipation efficiency can beimproved, by means of the protrusions whose tips have a shape incross-section that bulges outward toward the sides further than thebases thereof, and the grooves are received in between the adjacentprotrusions. In addition, by fitting the protrusions and grooves of therespective mounting substrate and heat dissipating fins, movement thatseparates the two members can be regulated, and thus they can bemaintained in the attached state without the use of attachment meanssuch as screws and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing one example of an electrical powercircuit for an air conditioner.

FIG. 2 is a lateral view showing an example of the substrate structureof a power module.

FIG. 3 is a lateral view showing another example of the substratestructure of the power module.

FIG. 4 is a perspective view showing an example of the substratestructure of the power module.

FIG. 5 is a perspective view showing another example of the substratestructure of the power module.

FIG. 6 is a perspective view showing an example of the heat dissipatingsurface of the aluminum substrate.

FIG. 7 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

FIG. 8 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

FIG. 9 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

FIG. 10 is a perspective view showing another example of the heatdissipating surface of the aluminum substrate.

FIG. 11 is a perspective view showing an example of the attachmentsurface of the heat dissipating fins.

FIG. 12 is a perspective view showing another example of the attachmentsurface of the heat dissipating fins.

FIG. 13 is a perspective view showing another example of the attachmentsurface of the heat dissipating fins.

FIG. 14 is a perspective view showing another example of the attachmentsurface of the heat dissipating fins.

FIG. 15 is a perspective view showing another example of the attachmentsurface of the heat dissipating fins.

FIG. 16 is a perspective view showing another example of the attachmentstructure of the aluminum substrate and the heat dissipating fins.

FIG. 17 is a perspective view showing another example of the attachmentstructure of the aluminum substrate and the heat dissipating fins.

FIG. 18 is a perspective view showing another example of the attachmentstructure of the aluminum substrate and the heat dissipating fins.

FIG. 19 shows an example in which the heat dissipating fins are disposedon a surface of the aluminum substrate that is opposite the mountingsurface thereof.

BEST MODE FOR CARRYING OUT THE INVENTION

(Structure of the Modulized Electric Power Circuit)

The details of a power module according to the present invention will bedescribed with reference to the figures.

FIG. 1 is a block diagram showing an example of an electric powercircuit that is employed in an air conditioner.

As shown in FIG. 1, the electric power circuit is connected to acommercial ac power source 1, and the ac power is supplied to a controlpower unit 2 and a modulized electric power circuit 3.

The control power unit 2 is made up of a switching power supply, andsupplies electrical power to a RA controller 4 that includes amicroprocessor, ROM, and various types of interfaces. Detection signalsfrom a plurality of sensors 5 are input into the RA controller 4. Thesesensors 5 include an outside air thermistor that detects the temperatureof the outside air, a heat exchange thermistor that detects theevaporation temperature and the condensing temperature of a heatexchanger, a discharge line temperature sensor that detects thedischarge line temperature of a compressor, and an intake pressuresensor that detects the intake pressure of a compressor. In addition, aplurality of actuators 6 are connected to and controlled by the RAcontroller 4, and include an electric expansion valve that is disposedin the refrigerant circuit and serves to reduce the pressure of therefrigerant therein, and a four way directional control valve whichserves to switch the operational mode of the refrigerant circuit.

The electric power circuit 3 primarily serves to control the electricalpower that drives a compressor 7 and a fan motor 8 in response to theoperational state of the air conditioner, and is comprised of aconverter 31 that rectifies the ac power supplied from the ac powersource 1 and converts it to dc power, an inverter 32 that converts theoutput of the converter 31 to ac power, a converter driver 33 whichserves to drive the converter 31, an inverter driver 34 which serves todrive the inverter 32, a fan motor controller 37 that generates a powersupply for driving the fan motor 8, a controller 35 that controls theconverter driver 33, the inverter driver 34, and the fan motorcontroller 37, and a communication circuit 36 which transmits andreceives data between the RA controller 4 and the electric power circuit3.

The converter 31 can be configured as a power switch, and can beconfigured to include an active filter circuit that outputs dc power ata fixed voltage with respect to the inverter 32.

The fan motor 8 can use an inverter circuit and an inverter driverdisposed therein. In this situation, the fan motor 8 is configured suchthat the output of the converter 31 is supplied thereto, and rotationalcontrol thereof occurs based on rotational speed command signals thatare input from the fan motor controller 37.

As noted above, the fan motor controller 37 is configured such that itoutputs the rotational speed command signals for the fan motor 8. Insituations in which the fan motor 8 does not use an inverter circuitdisposed therein, it can be configured like the controller for thecompressor 7 to include an inverter, and inverter driver, and the like.

The RA controller 4 determines the control variables for each unit inresponse to the detected values input from the sensors 5 and the currentoperational mode, outputs control values to the actuators 6, andtransmits control variables for the compressor 7 and the fan motor 8 tothe controller 35 inside the electrical power circuit 3 via thecommunication circuit 36.

The controller 35 outputs control values to the converter driver 33, theinverter driver 34, and the fan motor controller 37 based upon thecontrol variables for the compressor 7 and the fan motor 8 transmittedfrom the RA controller 4. Thus, the operational frequency of thecompressor 7 and the rotational frequency of the fan motor 8 can becontrolled in response to the operational state of the air conditioner.

By integrating and modulizing the circuit components, and packaging theheat generating and noise generating components, the controllability ofthe electric power circuit 3 can be improved, and high performancecontrol thereof can be performed. In other words, as shown in FIG. 2,the electric power circuit 3 is comprised of a plurality of bare chipcomponents 311, 312, and 313 such as a diode and power transistor,smoothing condenser, IC chip, and the like that are each mounted on analuminum substrate 301 by means of wire bonding, solder, and the like.

The aluminum substrate 301 can, for example, be comprised of a sheet ofaluminum nitride having high thermal conductivity and excellentelectrical resistance, and a thin sheet of copper that forms a circuitpattern that is adhered to the surface thereof. If a harness is used toconnect the controller 35, converter 31, inverter 32, converter driver33, inverter driver 34, fan motor controller 37 and the communicationcircuit 36, the harness will be a bundle of connections and willgenerate emission noise in the same way a coil does. By using analuminum substrate 301 that is comprised of a thin copper sheet thatforms a circuit pattern and an aluminum nitride sheet that has the thincopper sheet applied to the surface thereof, the generation of emissionnoise can be suppressed, and an increase in controllability due to areduction in noise can be provided.

Circuit components that have a high heat output are mounted directly tothe aluminum substrate 301, such as the bare chip components 311 and312. In addition, the bare chip component 313, such as the controller 35comprised of a one chip microcomputer that includes a microprocessor,ROM, various interfaces, and the like, is to be separated from thetemperature load and noise generated by other circuit components and canbe mounted on top of a standard printed wiring board 321. A lead 322provided on the printed wiring board 322 can be mounted on the aluminumsubstrate 301 by soldering. As shown in FIG. 2, the printed wiring board321 can be disposed at a right angle to the mounting surface of thealuminum substrate 301, and as shown in FIG. 3, the printed wiring board321 can also be disposed parallel to the mounting surface of thealuminum substrate 301.

Thus, by mounting precision components such as microcomputers and thelike to the printed wiring board 321 in a hybrid manner, unnecessarytemperature loads from other circuit components that have high heatoutputs can be eliminated, and the effects on noise due to the powerswitch and the like can be reduced.

The interior of the electric power circuit 3 is a non-insulatedstructure, and is configured such that the controller 35 transmits datato and receives data from the exterior thereof via the communicationcircuit 36. Thus, the packaging density of each circuit component can beincreased and a reduction in the size of the module can be provided,because the communication circuit 36 insulates the electric powercircuit 3 from the exterior thereof and the insulating distance of themodule interior is shortened.

As noted above, a molding material that molds both the bare chipcomponents 311, 312 and the bare chip component 313 installed on themounting surface of the aluminum substrate 301 is provided on top of thealuminum substrate 301.

As shown in FIG. 2, if the printed wiring board 321 is installed on themounting surface of the aluminum substrate 301 such that it isperpendicular thereto, the molding material can be arranged such that itcovers the bare chip components 311, 312 and the lead 322 of the printedwiring board 321 directly installed thereon. In addition, the moldingmaterial can also be structured such that one molding material coversbare chip components 311, 312 having equal thicknesses, and anothermolding material covers only the area around the printed wiring board321. In this situation, it is preferable that the molding material thatcovers only the area around the printed circuit board 321 be moreadhesive than the molding material that covers the bare chip components311, 312.

In addition, as shown in FIG. 3, if the printed wiring board 321 isdisposed parallel with respect to the mounting surface of the aluminumsubstrate 301, a molding material can be provided that covers all of thecircuit components. Moreover, a molding material can be provided thatcovers only the bare chip components 311, 312 and the lead 322 providedon the printed wiring board 321. Furthermore, the molding material canalso be structured such that one molding material covers bare chipcomponents 311, 312 having equal thicknesses, and another moldingmaterial covers only the area around the printed wiring board 321. Inthis situation also, it is preferable that the molding material thatcovers only the area around the printed circuit board 321 be moreadhesive than the molding material that covers the bare chip components311, 312.

The molding material is comprised of an insulating synthetic resin. Forexample, a silicone or epoxy resin can be employed.

The molding material can be applied such that it covers each circuitcomponent mounted on the aluminum substrate 301. However, in order toachieve improved insulation capabilities, a case can be formed on theupper surface of the aluminum substrate 301, and the molding materialcan be disposed inside the case. An example of this configuration isshown in FIG. 4.

As shown in FIG. 4, side walls 351, 352, 353, 354 are formed on theedges of the aluminum substrate 301 and extend toward the mountingsurface side thereof. Side walls 351–354 can be formed from aluminumnitride, like the aluminum substrate 301, or can be formed from aninsulating synthetic resin. In addition, the side walls 351–354 arefixed to the respective edges of the aluminum substrate 301 by thermallymelting them thereto, adhering them thereto, or the like, and theportions of the side walls 351–354 that are adjacent thereto are fixedto each other by means of thermal melting, adhesives, or the like sothat there are no gaps therebetween. Note that it is also possible tounitarily mold the side walls 351–354 such that they are integral witheach other.

As noted above, the molding material 341 is disposed in the empty spaceon the mounting surface side of the aluminum substrate 301 that isformed by the aluminum substrate 301 and the side walls 351–354. Themolding material 341 is arranged such that it covers the bare chipcomponents 311, 312, etc. that are mounted on the aluminum substrate 301as well as their wiring portions.

This configuration prevents the infiltration of corrosion, dust, andsmall animals therein, and also prevents accidents such as cut wires andshort-circuiting. In addition, a frame structure that surrounds thealuminum substrate 301 can be formed with side walls 351–354 that areintegrally formed or in which each side is combined with the others, anda case can be formed for mold filling by fixing the side walls 351–354to the aluminum substrate such that there are no gaps therebetween.Thus, all surfaces of the bare chip components 311, 312, etc. and theirwiring portions can be easily covered, and reliability will be improvedthereby. Furthermore, a case structure can be achieved by means of theside walls 351–354 and the aluminum substrate 301, and the thickness ofthe molding can be freely adjusted so that it covers each circuitcomponent to a necessary and sufficient degree. In other words, by usingthe side walls 351–354 that surround the periphery of the aluminumsubstrate 301 to prevent the molding material from flowing out, thethickness of the molding material can be freely adjusted.

As shown in FIG. 5, side walls 361–364 that are comprised of a syntheticresin in which a conductive pattern formed of copper has been embeddedtherein can be substituted for the side walls 351–354 shown in FIG. 4.

The side walls 361–364 are formed by inserting a conductive pattern madeof copper sheet into a metal mold, and then integrally molding the sidewalls 361–364 by using a insulating synthetic resin. The side walls361–364 can also be molded individually, or can be molded so that theyare all integral with each other. The side walls 361–364 that are formedin this manner are fixed to the aluminum substrate 301 by means ofthermal melting, adhesives, screws, or the like. Preferably, the case isstructured such that there are no gaps between the aluminum substrate301 and the side walls 361–364, and between the portions of the sidewalls 361–364 that are adjacent to each other.

The molding material 341 is placed into the space on the mountingsurface side of the aluminum substrate 301 that is formed by thealuminum substrate 301 and the side walls 361–364. The molding material341 is disposed such that it covers the bare chip components 311, 312,etc. that are mounted on the aluminum substrate 301 and their wiringportions.

The conductive pattern embedded in the interior of the side walls361–364 forms a wiring pattern for installing large external circuitcomponents 371–373 such as electrolytic capacitors. Thus, these externalcircuit components 371–373 can be installed at the proper positions onthe side walls 361–364 with solder or the like. FIG. 5 shows an examplein which the external circuit components 371–373 are installed on theouter surface of the side wall 361. However, if there is open spaceabove the molding material 341, it is also possible to install theexternal circuit components on the interior surfaces of the side walls361–364.

This arrangement makes three dimensional mounting of components possibleby mounting the circuit components on the side surfaces of the case ofthe module, and can increase the integration ratio. In addition, thisarrangement can also serve as an installation retention unit for circuitcomponents such as large electrolytic condensers, thereby increasing theintegration ratio, and reducing the size of the device.

In this embodiment, it is also possible to substitute a ceramicsubstrate or the like for the aluminum substrate 301.

(Aluminum Substrate)

If an aluminum substrate is used as the mounting substrate on which barechip components 311, 312, printed wiring board 321, and the like aremounted, a corrugated section can be disposed on the opposite surfacethereof in order to form a heat dissipation surface. Examples of heatdissipation surfaces that are formed by corrugated sections are shown inFIGS. 6 to 10.

An aluminum substrate 401 shown in FIG. 6 has a power module 300 mountedthereon that has, as noted above, been molded from a synthetic resin. Acorrugated section 404 comprised of protrusions 402 that are rectangularin cross-section and formed parallel to each other, and grooves 403 thatare formed in between adjacent protrusions 402, is formed on the lowersurface of the aluminum substrate 401.

The corrugated section 404 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 402that are rectangular in cross-section and formed parallel to each other,and grooves 403 that are formed in between adjacent protrusions 402.

An aluminum substrate 411 shown in FIG. 7 has a power module 300 mountedthereon that has, as noted above, been molded from a synthetic resin. Acorrugated section 414 comprised of protrusions 412 that are triangularin cross-section and formed parallel to each other, and grooves 413 thatare formed in between adjacent protrusions 412, is formed on the lowersurface of the aluminum substrate 411.

The corrugated section 414 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 412that are triangular in cross-section formed parallel to each other, andgrooves 413 that are formed in between adjacent protrusions 412.

An aluminum substrate 421 shown in FIG. 8 has a power module 300 mountedthereon that has, as noted above, been molded from a synthetic resin. Acorrugated section 424 comprised of protrusions 422 that are trapezoidalin cross-section and formed parallel to each other, and grooves 423 thatare formed in between adjacent protrusions 422, is formed on the lowersurface of the aluminum substrate 421.

The corrugated section 424 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 422that are trapezoidal in cross-section and formed parallel to each other,and grooves 423 that are formed in between adjacent protrusions 422.

An aluminum substrate 431 shown in FIG. 9 has a power module 300 mountedthereon that has, as noted above, been molded from a synthetic resin. Acorrugated section 434 comprised of protrusions 432 that aresemicircular in cross-section and formed parallel to each other, andgrooves 433 that are formed in between adjacent protrusions 432, isformed on the lower surface of the aluminum substrate 431.

The corrugated section 434 has a large surface area and a greatlyimproved heat dissipation efficiency, because of the protrusions 432that are semicircular in cross-section and formed parallel to eachother, and grooves 433 that are formed in between adjacent protrusions432.

An aluminum substrate 441 shown in FIG. 10 has a power module 300mounted thereon that has, as noted above, been molded from a syntheticresin. A corrugated section 444 comprised of a plurality of protrusions442 that have a hemisphere formed on each of the tips thereof is formedon the lower surface of the aluminum substrate 441.

The corrugated section 444 has a large surface area and a greatlyimproved heat dissipation efficiency because of the protrusions 442.

(Heat Dissipating Fins)

Heat dissipating fins that are comprised of an attachment surface whichattaches to a corrugated section provided on the lower surface of thealuminum substrate, and a plurality of plate shaped fins, can beinstalled on the lower surface of the aluminum substrate. Examples ofthis type of heat dissipating fins are shown in FIGS. 11–15.

The heat dissipating fins 501 shown in FIG. 11 are installed on thealuminum substrate 401 shown in FIG. 6, and comprise an attachmentsurface 504 on one side thereof that attaches to the corrugated section404 of the aluminum substrate 401. The attachment surface 504 iscomprised of protrusions 502 that are rectangular in cross-section andfit into the grooves 403 of the aluminum substrate 401, and grooves 503that accept the protrusions 402 of the aluminum substrate 401. Theattachment surface 504 can be adhered to the corrugated section 404 ofthe aluminum substrate 401.

The heat dissipating fins 501 are comprised of a plurality of plateshaped fin members 505 that project from the side opposite theattachment surface 504. The fin members 505 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 501, like the aluminum substrate 401, can becomprised of a material such as aluminum nitride having high thermalconductivity and excellent insulation characteristics, and can beproduced with a processing method such as drawing or punching.

The heat dissipating fins 501 are attached such that the attachmentsurface 504 is adhered to the corrugated section 404 of the aluminumsubstrate 401, and are adhered thereto with an attachment method such asscrewing, thermal melting, or by means of a resin material.

When constructed in this manner, there is a large attachment surfacearea between the corrugated section 404 of the aluminum substrate 401and the attachment surface 504 of the heat dissipating fins 501, andthus the thermal conduction efficiency from the aluminum substrate 401to the heat dissipating fins 501 will be excellent, and the heatgenerated by the power module 300 can be dissipated more efficientlywith the fin members 505 of the heat dissipating fins 501.

The heat dissipating fins 511 shown in FIG. 12 are installed on thealuminum substrate 411 shown in FIG. 7, and comprise an attachmentsurface 514 on one side thereof that attaches to the corrugated section414 of the aluminum substrate 411. The attachment surface 514 iscomprised of protrusions 512 that are triangular in cross-section andfit into the grooves 413 of the aluminum substrate 411, and grooves 513that accept the protrusions 412 of the aluminum substrate 411. Theattachment surface 514 can be adhered to the corrugated section 414 ofthe aluminum substrate 411.

The heat dissipating fins 511 are comprised of a plurality of plateshaped fin members 515 that project from the side opposite theattachment surface 514. The fin members 515 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 511, like the heat dissipating fins 501 notedabove, can be comprised of a material such as aluminum nitride havinghigh thermal conductivity and excellent insulation characteristics, andcan be produced with a processing method such as drawing or punching.

The heat dissipating fins 511 are attached such that the attachmentsurface 514 is adhered to the corrugated section 414 of the aluminumsubstrate 411, and are adhered thereto with an attachment method such asscrewing, thermal melting, or by means of a resin material.

When constructed in this manner, there is a large attachment surfacearea between the corrugated section 414 of the aluminum substrate 411and the attachment surface 514 of the heat dissipating fins 511, andthus the thermal conduction efficiency from the aluminum substrate 411to the heat dissipating fins 511 will be excellent, and the heatgenerated by the power module 300 can be dissipated more efficientlywith the fin members 515 of the heat dissipating fins 511.

The heat dissipating fins 521 shown in FIG. 13 are installed on thealuminum substrate 421 shown in FIG. 8, and comprise an attachmentsurface 524 on one side thereof that attaches to the corrugated section424 of the aluminum substrate 421. The attachment surface 524 iscomprised of protrusions 522 that are trapezoidal in cross-section andfit into the grooves 423 of the aluminum substrate 421, and grooves 523that accept the protrusions 422 of the aluminum substrate 421. Theattachment surface 524 can be adhered to the corrugated section 424 ofthe aluminum substrate 421.

The heat dissipating fins 521 are comprised of a plurality of plateshaped fin members 525 that project from the side opposite theattachment surface 524. The fin members 525 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 521, like the heat dissipating fins 501 notedabove, can be comprised of a material such as aluminum nitride havinghigh thermal conductivity and excellent insulation characteristics, andcan be produced with a processing method such as drawing or punching.

The heat dissipating fins 521 are attached such that the attachmentsurface 524 is adhered to the corrugated section 424 of the aluminumsubstrate 421, and are adhered thereto with an attachment method such asscrewing, thermal melting, or by means of a resin material.

When constructed in this manner, there is a large attachment surfacearea between the corrugated section 424 of the aluminum substrate 421and the attachment surface 524 of the heat dissipating fins 521, andthus the thermal conduction efficiency from the aluminum substrate 421to the heat dissipating fins 521 will be excellent, and the heatgenerated by the power module 300 can be dissipated more efficientlywith the fin members 525 of the heat dissipating fins 521.

The heat dissipating fins 531 shown in FIG. 14 are installed on thealuminum substrate 431 shown in FIG. 9, and comprise an attachmentsurface 534 on one side thereof that attaches to the corrugated section434 of the aluminum substrate 431. The attachment surface 534 iscomprised of protrusions 532 that are semicircular in cross-section andfit into the grooves 433 of the aluminum substrate 431, and grooves 533that accept the protrusions 432 of the aluminum substrate 431. Theattachment surface 534 can be adhered to the corrugated section 434 ofthe aluminum substrate 431.

The heat dissipating fins 531 are comprised of a plurality of plateshaped fin members 535 that project from the side opposite theattachment surface 534. The fin members 535 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 531, like the heat dissipating fins 501 notedabove, can be comprised of a material such as aluminum nitride havinghigh thermal conductivity and excellent insulation characteristics, andcan be produced with a processing method such as drawing or punching.

The heat dissipating fins 531 are attached such that the attachmentsurface 534 is adhered to the corrugated section 434 of the aluminumsubstrate 431, and are adhered thereto with an attachment method such asscrewing, thermal melting, or by means of a resin material.

When constructed in this manner, there is a large attachment surfacearea between the corrugated section 434 of the aluminum substrate 431and the attachment surface 534 of the heat dissipating fins 531, andthus the thermal conduction efficiency from the aluminum substrate 431to the heat dissipating fins 531 will be excellent, and the heatgenerated by the power module 300 can be dissipated more efficientlywith the fin members 535 of the heat dissipating fins 531.

The heat dissipating fins 541 shown in FIG. 15 are installed on thealuminum substrate 441 shown in FIG. 10, and comprise an attachmentsurface 544 on one side thereof that attaches to the corrugated section444 of the aluminum substrate 441. The attachment surface 544 iscomprised of a plurality of concave portions 543 into which fit theprotrusions 442 of the aluminum substrate 441. The attachment surface544 can be adhered to the corrugated section 444 of the aluminumsubstrate 441.

The heat dissipating fins 541 are comprised of a plurality of plateshaped fin members 545 that project from the side opposite theattachment surface 544. The fin members 545 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 541, like the heat dissipating fins 501 notedabove, can be comprised of a material such as aluminum nitride havinghigh thermal conductivity and excellent insulation characteristics, andcan be produced with a processing method such as drawing or punching.

The heat dissipating fins 541 are attached such that the attachmentsurface 544 is adhered to the corrugated section 444 of the aluminumsubstrate 441, and are adhered thereto with an attachment method such asscrewing, thermal melting, or by means of a resin material.

When constructed in this manner, there is a large attachment surfacearea between the corrugated section 444 of the aluminum substrate 441and the attachment surface 544 of the heat dissipating fins 541, andthus the thermal conduction efficiency from the aluminum substrate 441to the heat dissipating fins 541 will be excellent, and the heatgenerated by the power module 300 can be dissipated more efficientlywith the fin members 545 of the heat dissipating fins 541.

(Attachment Structure for Aluminum Substrate and Heat Dissipating Fins)

Attachment structures for installing the heat dissipating fins to theheat dissipating surface of the aluminum substrate that are differentthan the embodiments noted above can be considered. For example, assumethat each of the tips of the protrusions provided on the heatdissipating surface of the aluminum substrate have a shape incross-section that bulges out toward the sides thereof further than thebase thereof, and that the shape of each groove positioned between eachprotrusion allows each protrusion provided on the attachment surface ofthe heat dissipating fins to be received therein. Further assume thatwith the protrusions provided on the attachment surface of the heatdissipating fins, each of the tips thereof have a shape in cross-sectionthat bulges out toward the sides thereof further than the base thereof,and that the shape of each groove positioned between each protrusionallows each protrusion provided on the aluminum substrate to be receivedtherein. This configuration allows the aluminum substrate and the heatdissipating fins to be maintained in the attached state even if noscrews are used. Embodiments of this configuration are described inFIGS. 16–18.

An aluminum substrate 451 shown in FIG. 16 mounts the power module 300that was molded by means of the synthetic resin noted above. Acorrugated section 456 is formed on the lower surface thereof, whichcomprises protrusions 454 that are formed such that they are parallelwith each other, and grooves 455 that are formed between adjacentprotrusions 454. Each protrusion 454 is comprised of a base 452 and atip 453 that bulges out toward the sides further than the base 452, andare T shaped in cross-section.

The heat dissipating fins 551 have, on one surface thereof, anattachment surface 556 that attaches to the corrugated section 456 ofthe aluminum substrate 451. The attachment surface 556 is comprised ofprotrusions 554 that fit into the grooves 455 of the aluminum substrate451, and grooves 555 that receive the protrusions 454 of the aluminumsubstrate 451. The attachment surface 556 can be adhered to thecorrugated section 456 of the aluminum substrate 451. Each protrusion554 is comprised of a base 552 and a tip 553 that bulges out toward thesides further than the base 552, and are T shaped in cross-section.

The heat dissipating fins 551 are comprised of a plurality of plateshaped fin members 557 that project from the side opposite theattachment surface 556. The fin members 557 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 557, like the aluminum substrate 451, can becomprised of a material such as aluminum nitride having high thermalconductivity and excellent insulation characteristics, and can beproduced with a processing method such as drawing or punching.

The protrusions 454 of the aluminum substrate 451 are fitted into thegrooves 555 of the heat dissipating fins 551. By fitting the protrusions554 of the heat dissipating fins 551 into the grooves 455 of thealuminum substrate 451, and sliding each protrusion 454, 554 parallel toeach other, the attachment surface 556 of the heat dissipating fins 551can be attached to the corrugated section 456 of the aluminum substrate451.

Thus, by engaging the protrusions 454 and grooves 455 of the aluminumsubstrate 451 and the protrusions 554 and grooves 555 of the heatdissipating fins 551, movement that separates the aluminum substrate 451and the heat dissipating fins 551 can be regulated, and thus they can bemaintained in the attached state. In this way, the thermal conductionefficiency between the aluminum substrate 451 and the heat dissipatingfins 551 can be maintained at a high level, and screws and the like usedfor installation can be omitted.

An aluminum substrate 461 shown in FIG. 17 mounts the power module 300that was molded by means of the synthetic resin noted above. Acorrugated section 466 is formed on the lower surface thereof, whichcomprises protrusions 464 that are formed such that they are parallelwith each other, and grooves 465 that are formed between adjacentprotrusions 464. Each protrusion 464 is comprised of a base 462 and atip 463 that bulges out toward the sides further than the base 462. Theprotrusions 464 and the grooves 465 are shaped such that a cross-sectionof the corrugated section 466 is a combination of round or ellipticalcurves.

The heat dissipating fins 561 have, on one surface thereof, anattachment surface 566 that attaches to the corrugated section 466 ofthe aluminum substrate 461. The attachment surface 566 is comprised ofprotrusions 564 that fit into the grooves 465 of the aluminum substrate461, and grooves 565 that receive the protrusions 464 of the aluminumsubstrate 461. The attachment surface 566 can be adhered to thecorrugated section 466 of the aluminum substrate 461. Each protrusion564 is comprised of a base 562 and a tip 563 that bulges out toward thesides further than the base 562. The protrusions 564 and the grooves 565are shaped such that a cross-section of the corrugated section 566 is acombination of round or elliptical curves.

The heat dissipating fins 561 are comprised of a plurality of plateshaped fin members 567 that project from the side opposite theattachment surface 566. The fin members 567 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 567, like the aluminum substrate 461, can becomprised of a material such as aluminum nitride having high thermalconductivity and excellent insulation characteristics, and can beproduced with a processing method such as drawing or punching.

Like with the aforementioned embodiment, the protrusions 464 of thealuminum substrate 461 are fitted into the grooves 565 of the heatdissipating fins 561. By fitting the protrusions 564 of the heatdissipating fins 561 into the grooves 465 of the aluminum substrate 461,and sliding each protrusion 464, 564 parallel to each other, theattachment surface 566 of the heat dissipating fins 561 can be attachedto the corrugated section 466 of the aluminum substrate 461.

Thus, by engaging the protrusions 464 and grooves 465 of the aluminumsubstrate 461 and the protrusions 564 and grooves 565 of the heatdissipating fins 561, movement that separates the aluminum substrate 461and the heat dissipating fins 561 can be regulated, and thus they can bemaintained in the attached state. In this way, the thermal conductionefficiency between the aluminum substrate 461 and the heat dissipatingfins 561 can be maintained at a high level, and screws and the like usedfor installation can be omitted.

An aluminum substrate 471 shown in FIG. 18 mounts the power module 300that was molded by means of the synthetic resin noted above. Acorrugated section 476 is formed on the lower surface thereof, whichcomprises protrusions 472 that are formed such that they are parallelwith each other, and grooves 473 that are formed between adjacentprotrusions 472. Each protrusion 472 is comprised of an upside downtrapezoid (in cross-section) that bulges out toward the sides furtherthan the base thereof.

The heat dissipating fins 561 have, on one surface thereof, anattachment surface 574 that attaches to the corrugated section 476 ofthe aluminum substrate 471. The attachment surface 574 is comprised ofprotrusions 572 that fit into the grooves 473 of the aluminum substrate471, and grooves 573 that receive the protrusions 472 of the aluminumsubstrate 471. The attachment surface 574 can be adhered to thecorrugated section 474 of the aluminum substrate 471. Each protrusion572 is comprised of an upside down trapezoid (in cross-section) thatbulges out toward the sides further than the base thereof.

The heat dissipating fins 571 are comprised of a plurality of plateshaped fin members 575 that project from the side opposite theattachment surface 574. The fin members 575 are formed to be thin inorder to enlarge the surface area, and are disposed with a predetermineddistance between each other in order to increase the heat dissipationefficiency thereof.

The heat dissipating fins 571, like the aluminum substrate 471, can becomprised of a material such as aluminum nitride having high thermalconductivity and excellent insulation characteristics, and can beproduced with a processing method such as drawing or punching.

Like with the aforementioned embodiment, the protrusions 472 of thealuminum substrate 471 are fitted into the grooves 573 of the heatdissipating fins 571. By fitting the protrusions 573 of the heatdissipating fins 571 into the grooves 472 of the aluminum substrate 471,and sliding each protrusion 472, 572 parallel to each other, theattachment surface 574 of the heat dissipating fins 571 can be attachedto the corrugated section 474 of the aluminum substrate 471.

Thus, by engaging the protrusions 472 and grooves 473 of the aluminumsubstrate 471 and the protrusions 572 and grooves 573 of the heatdissipating fins 571, movement that separates the aluminum substrate 471and the heat dissipating fins 571 can be regulated, and thus they can bemaintained in the attached state. In this way, the thermal conductionefficiency between the aluminum substrate 471 and the heat dissipatingfins 571 can be maintained at a high level, and screws and the like usedfor installation can be omitted.

The shapes of the corrugated section of the aluminum substrate and theheat dissipating fins are not limited to the shapes shown in thefigures, but can be any shape that provides excellent thermal conductionefficiency. In addition, the circuit structure inside the module is notlimited to that shown in the figures, and the corrugated section of thealuminum substrate and the heat dissipating fins can be applied to avariety of modules which comprise circuit components that are thought toproduce a great deal of heat.

As shown in FIG. 19, heat dissipating fins 331 can be simply attacheddirectly to the surface opposite the mounting surface of the aluminumsubstrate 301. The heat dissipating fins 331 can be integrally andsimultaneously formed with the aluminum nitride plate that forms thealuminum substrate 301, or can be attached to the aluminum substrate 301by thermally melting them thereto or adhering them thereto.

If the heat dissipating plates 301 are formed to be integral with thesurface opposite the bare chip component mounting surface of thealuminum substrate 301, it will not be necessary to install separateheat dissipating fins, and it will be possible to improve the heatconduction efficiency of the aluminum substrate 301.

INDUSTRIAL APPLICABILITY

In the power module according to claim 1 of the present invention, theconnection between the bare chip components and the wiring on themounting substrate can be formed by wire bonding and the like. Becausethis wiring is molded by means of the molding material, the wiring canbe shortened and the effects of noise can be eliminated. In addition,because exposed portions will be eliminated, the effects from theinfiltration of corrosion, dust, and small animals can be prevented.

In the power module according to claim 2 of the present invention, theconnection between the bare chip components and the wiring on themounting substrate can be formed by wire bonding and the like. Becausethis wiring is molded by means of the molding material, the wiring canbe shortened. When a large number of components generate heat, the powermodule can be constructed such that the heat is dissipated via thealuminum substrate.

In the power module according to claim 3 of the present invention,circuit components that produce a great deal of heat can be insulatedfrom those that produce comparatively little heat by forming the printedwiring board on which the comparatively low heat generating circuitcomponents are mounted into a hybrid shape.

In the power module according to claim 4 of the present invention, ifcomparatively high heat generating circuit components are mounted on topof the mounting substrate as bare chip components, heat can beefficiently dissipated therefrom via the heat dissipating fins, andcircuit malfunctions can be prevented by maintaining them at a suitabletemperature.

In the power module according to claim 5 of the present invention, thetask of filling the space formed by the mounting substrate and the sidewalls with the molding material can be made easy, and the bare chipcomponent mounting surface of the mounting substrate can be accuratelymolded.

In the power module according to claim 6 of the present invention, it ispossible to use the conductive pattern embedded in the interior of theside walls to connect the circuit elements, and it is possible to mountcircuit elements such as electrolytic condensers and the like that aredifficult to integrate.

In the power module according to claim 7 of the present invention, bydirectly mounting the inverter circuit and the controller for theinverter circuit to the mounting substrate as bare chip components andmodulizing them, it will not be necessary to again consider the spatiallayout and thermal design of each component, the ill effects of noisewill be eliminated to the greatest degree possible by shortening thewiring distances, and ill effects from the infiltration of corrosion,dust and small animals will be prevented.

In the power module according to claim 8 of the present invention, eachpower module can be comprised of one or a plurality of bare chipcomponents, and the bare chip components can be mounted on the aluminumsubstrate. Thus, it will not be necessary to again consider the spatiallayout and thermal designs thereof.

In the power module according to claim 9 of the present invention, bymodulizing the inverter circuit that controls the compressor of the airconditioner, the size of the device can be reduced, the ill effects ofnoise and the ill effects from the infiltration of corrosion, dust andsmall animals can be eliminated, and a highly reliable device can beprovided. In addition, by viewing the power module as one component andconducing structural design accordingly, it will not be necessary tohave a different structural design for each type of compressor mountedin the air conditioner, and thus the number of man-hours needed forstructural design with respect to the large number of different types ofcompressors available can be greatly reduced.

In the power module according to claim 10 of the present invention, thesize of the device can be reduced by mounting the fan motor controllercomprising bare chip components onto the aluminum substrate togetherwith other circuit components and modulizing them, thus eliminating theneed to again consider the spatial layout and thermal design thereof.

In the air conditioner according to claim 11 of the present invention,by modulizing the electric power unit of the air conditioner, the sizeof the device can be reduced, the ill effects of noise and the illeffects from the infiltration of corrosion, dust and small animals canbe eliminated, and a highly reliable device can be provided.

In the air conditioner according to claim 12 of the present invention,the ill effects of noise can be eliminated by modulizing the electricpower unit that serves to control the electric power supplied to thecompressor of the air conditioner. In addition, foreign objects such assmall animals and dust that enter into the electric power unit and causeproblems such as short circuiting and the like can be prevented.

In the air conditioner according to claim 13 of the present invention,the size of the device can be reduced by including and then modulizingthe fan motor controller that controls the rotation of the fan motor ofthe air conditioner, and thus a highly reliable device in which the illeffects of noise and the ill effects of the infiltration of corrosion,dust, and small animals are eliminated.

In the power module according to claim 14 of the present invention, theheat generated by the circuit components mounted on the mounting surfacecan be efficiently dissipated by means of the corrugated section formedon the heat dissipating surface of the mounting substrate.

In the power module according to claim 15 of the present invention, heatcan be efficiently dissipated from the heat dissipation surface even ifthe mounting surface is molded with an insulating synthetic resin and anenclosed type of module is formed.

In the power module according to claim 16 of the present invention, theheat from the circuit components mounted on the mounting surface can beefficiently dissipated because an aluminum having a high thermo-electricconductivity is used as the mounting substrate.

In the power module according to claim 17 of the present invention, theattachment surface of the heat dissipating fins has a corrugated shapesuch that it attaches to the heat dissipating surface of the mountingsubstrate, and the thermal conductive efficiency between the heatdissipating fins and the mounting substrate is improved. Thus, the heatgenerated from the circuit components mounted on the mounting substratecan be efficiently transmitted to the heat dissipating fins, and theefficiency of thermal dissipation can be improved.

In the power module according to claim 18 of the present invention, thesurface area of the heat dissipating fins of the mounting substrate canbe enlarged, and the heat dissipation efficiency can be improved, bymeans of the protrusions that are rectangular in cross-section and thegrooves formed in between the adjacent protrusions. In addition, whenthe heat dissipating fins are installed, the thermal dissipation effectcan be improved because the contact surface area between the heatdissipating surface of the mounting substrate and the attachment surfaceof the heat dissipating fins is enlarged, and the mutual thermaltransmission efficiency is improved.

In the power module according to claim 19 of the present invention, thesurface area of the heat dissipating fins of the mounting substrate canbe enlarged, and the heat dissipation efficiency can be improved, bymeans of the protrusions that are triangular in cross-section and thegrooves formed in between the adjacent protrusions. In addition, whenthe heat dissipating fins are installed, the thermal dissipation effectcan be improved because the contact surface area between the heatdissipating surface of the mounting substrate and the attachment surfaceof the heat dissipating fins is enlarged, and the mutual thermaltransmission efficiency is improved.

In the power module according to claim 20 of the present invention, thesurface area of the heat dissipating fins of the mounting substrate canbe enlarged, and the heat dissipation efficiency can be improved, bymeans of the protrusions that are trapezoidal in cross-section and thegrooves formed in between the adjacent protrusions. In addition, whenthe heat dissipating fins are installed, the thermal dissipation effectcan be improved because the contact surface area between the heatdissipating surface of the mounting substrate and the attachment surfaceof the heat dissipating fins is enlarged, and the mutual thermaltransmission efficiency is improved.

In the power module according to claim 21 of the present invention, thesurface area of the heat dissipating fins of the mounting substrate canbe enlarged, and the heat dissipation efficiency can be improved, bymeans of the protrusions that are semi-circular in cross-section and thegrooves formed in between the adjacent protrusions. In addition, whenthe heat dissipating fins are installed, the thermal dissipation effectcan be improved because the contact surface area between the heatdissipating surface of the mounting substrate and the attachment surfaceof the heat dissipating fins is enlarged, and the mutual thermaltransmission efficiency is improved.

In the power module according to claim 22 of the present invention, thesurface area of the heat dissipating fins of the mounting substrate canbe enlarged, and the heat dissipation efficiency can be improved, bymeans of the protrusions that are hemispherical in cross-section and thegrooves formed in between the adjacent protrusions. In addition, whenthe heat dissipating fins are installed, the thermal dissipation effectcan be improved because the contact surface area between the heatdissipating surface of the mounting substrate and the attachment surfaceof the heat dissipating fins is enlarged, and the mutual thermaltransmission efficiency is improved.

In the power module according to claim 23 of the present invention, thesurface area of the heat dissipating fins of the mounting substrate canbe enlarged, and the heat dissipation efficiency can be improved, bymeans of the protrusions whose tips are shaped in cross-section to bulgeoutward, with respect to the bases thereof, toward the sides and thegrooves are received in between the adjacent protrusions. In addition,by fitting the protrusions and grooves of the respective mountingsubstrate and heat dissipating fins, movement that separates the twomembers can be regulated, and thus they can be maintained in theattached state without the use of attachment means such as screws andthe like.

1. A power module, comprising: a bare chip component that comprises anelectrical power circuit for controlling electrical power; a mountingsubstrate including a surface on which the bare chip component ismounted; at least two side walls disposed on edges of the mountingsubstrate and extending above the surface on which the bare chipcomponent is mounted, at least one of the side walls having a conductivepattern embedded therein, the conductive pattern being electricallycoupled to the bare chip component, and the conductive pattern forming awiring pattern with exposed connection points to form one or moreexternal component mounting points for installing large external circuitcomponents at proper positions on the side walls; and a molding materialincluding an insulating resin that covers the bare chip component andmolds to the surface of the mounting substrate on which the bare chipcomponent is mounted.
 2. The power module according to claim 1, whereina plurality of bare chip components are mounted on the mountingsubstrate.
 3. The power module according to claim 1, wherein the barechip component includes an IC chip that is mounted on a printed wiringboard that is mounted on the mounting substrate.
 4. The power moduleaccording to claim 1, wherein the mounting substrate comprises heatdissipating fins that are integrally disposed on a surface opposite thesurface on which the bare chip component is mounted.
 5. The power moduleaccording to claim 1, wherein the molding material is disposed inside aspace formed by the mounting substrate and the side walls.
 6. The powermodule according to claim 1, wherein at least one of the side walls isformed from a synthetic resin.
 7. The power module according to claim 1,wherein the bare chip component comprises an inverter circuit thatconverts commercial ac power to ac power having a predeterminedfrequency, and a controller that controls the frequency output from theinverter circuit.
 8. The power module according to claim 7, wherein theinverter circuit includes a converter that rectifies commercial ac powerto dc power, an inverter that converts the output of the converter to acpower, a converter driver that drives the converter, and an inverterdriver that drives the inverter.
 9. The power module according to claim7, wherein the inverter circuit controls electric power supplied to acompressor in an air conditioner, the compressor controlling an amountof refrigerant circulating in a refrigerant circuit.
 10. The powermodule according to claim 9, wherein the air conditioner includes a fanthat produces an air flow that exchanges heat with refrigerant inside aheat exchanger disposed inside the refrigerant circuit, and a fan motorthat rotatively drives the fan; and the bare chip component furtherincludes a fan motor controller that controls rotation of the fan motor.11. An air conditioner having an air conditioning unit that exchangesheat between air drawn therein and refrigerant that circulates inside arefrigerant circuit and then supplies heat exchanged air to an indoorspace, and an electric power unit that controls electric power suppliedto the air conditioning unit, the electric power unit comprising: amodulized power module including a bare chip component including anelectric power circuit for controlling electric power; a mountingsubstrate including a surface on which the bare chip component ismounted; at least two side walls disposed on edges of the mountingsubstrate and extending above the surface on which the bare chip ismounted, at least one of the side walls having a conductive patternembedded therein, the conductive pattern being electrically coupled tothe bare chip component, and the conductive pattern forming a wiringpattern with exposed connection points to form one or more externalcomponent mounting points for installing large external circuitcomponents at proper positions on the side walls; and a molding materialincluding an insulating resin that covers the bare chip component andmolds to the surface of the mounting substrate on which the bare chipcomponent is mounted.
 12. The air conditioner according to claim 11,further comprising a compressor that controls the amount of refrigerantcirculating in the refrigerant circuit; and the bare chip componentbeing configured to control electric power that is supplied to thecompressor and including an inverter circuit that converts commercial acpower to ac power of a predetermined frequency, and a controller thatcontrols an output frequency of the inverter circuit.
 13. The airconditioner according to claim 11, further comprising a fan thatproduces an air flow that exchanges heat with refrigerant inside a heatexchanger disposed inside the refrigerant circuit, and a fan motorarranged to rotate the fan; and the bare chip component furthercomprises a fan motor controller that controls rotation of the fanmotor.
 14. A power module, comprising: a mounting substrate that isformed from a member having a high thermal conduction efficiency andwhich comprises a mounting surface on which an electric power circuitfor controlling electric power is mounted, and a heat dissipatingsurface on which a corrugated section for heat dissipation is formed,the mounting substrate having side walls, at least one of the side wallshaving a conductive pattern embedded therein, the conductive patternbeing electrically coupled to the electric power circuit, and theconductive pattern forming a wiring pattern with exposed connectionpoints to form one or more external component mounting points forinstalling large external circuit components at proper positions on theside walls.
 15. The power module according to claim 14, wherein themounting surface and the heat dissipating surface comprise a two-sidedmounting substrate.
 16. The power module according to claim 14, whereinat least one of the side walls is formed from an aluminum type of metaland the embedded conductive pattern is a copper wiring pattern formed onone side thereof.
 17. The power module according to claim 14, furthercomprising heat dissipating fins comprising an attachment surface thatattaches to the heat dissipating surface of the corrugated section, anda fin formation section on which plate shaped fins are disposed.
 18. Thepower module according to claim 14, wherein the corrugated section iscomprised of plate shaped protrusions having rectangular cross-sectionsand which are formed parallel to each other, and grooves that are formedbetween adjacent protrusions.
 19. The power module according to claim14, wherein the corrugated section includes plate shaped protrusionshaving triangular cross-sections and which are formed parallel to eachother, and grooves that are formed between adjacent protrusions.
 20. Thepower module according to claim 14, wherein the corrugated sectionincludes plate shaped protrusions having trapezoidal cross-sections andwhich are formed parallel to each other, and grooves that are formedbetween adjacent protrusions.
 21. The power module according to claim14, wherein the corrugated section includes plate shaped protrusionshaving semi-circular cross-sections and which are formed parallel toeach other, and grooves that are formed between adjacent protrusions.22. The power module according to claim 14, wherein the corrugatedsection includes a plurality of protrusions having tips thereof that arehemi-spherical in shape.
 23. The power module according to claim 17,wherein the heat dissipating surface of the mounting substrate and theattachment surface of the heat dissipating fins comprise protrusionswith tips, each of the tips having a shape in cross-section which bulgesoutward toward sides of the tip farther than a base of the tip, andgrooves which are received in between adjacent protrusions.